Best Generator Interlock Kits for Panel Safety and Backfeed Prevention
Answering the question of how to safely backfeed a portable generator without risking your main system, these interlock kits are designed to prevent both mains and generator power from flowing simultaneously. They’re best for homeowners seeking reliable, code-friendly gear to manage generator power across common panel types. The top picks here cover Square D, Eaton/Cutler Hammer, General Electric, Siemens/Murray, and broader compatibility options. The buyer’s guide below highlights which kit suits specific panel models and installation needs.
| Product | Brand |
|---|---|
| Natupal Generator Interlock Kit | Natupal |
| EXCELFU Generator Interlock Kit (BR Series) | EXCELFU |
| SPZOCE GE Interlock Kit | SPZOCE |
| QYZZRS Eaton Cutler Hammer Interlock (100/125 Amp) | QYZZRS |
| XMK Siemens/Murray Interlock Kit | XMK |
Natupal Interlock Kit for Square D QO or Homeline Panels
Best for Square D QO and Homeline installations, this interlock kit provides a defined 1 3/8 inch spacing between the main and generator breaker. It is designed to safely route generator power to your home’s circuits during outages. It is especially suitable for homeowners with 150 or 200 amp panels seeking a straightforward installation. A shorter note: ensure your panel type matches Square D QO or Homeline family before purchasing.
Who it’s best for: homeowners with Square D QO/Homeline 150/200 amp panels who want a proven interlock approach that minimizes backfeed risk. Why selected: clear spacing specification and a professional-grade interlock that aligns with common residential panel configurations. Caution: verify model compatibility with your exact panel model and main/branch breaker arrangement before installation.
Key features: compatible with Square D QO/Homeline panels, 1 3/8 inch spacing between main and generator breaker, safety-focused interlock design to prevent accidental backfeeding.
EXCELFU Interlock Kit for Eaton Cutler Hammer BR Series
Best for Eaton/Cutler Hammer BR and CH series panels, this horizontal interlock kit supports 150 and 200 amp configurations with a 1 1/4 inch to 1 7/16 inch spacing between main and branch breakers. It provides a safe, cost-effective backfeed solution for emergency power. It’s particularly suitable for users who favor a horizontal configuration and want a straightforward installation process. Caution: verify the exact BR/CH configuration and neutral handling for your panel model.
Who it’s best for: homeowners with Eaton/Cutler Hammer BR or CH panels seeking a reliable backfeed solution. Why selected: compatible with common BR/CH 150/200 amp setups and designed for a clear, single-handle operation. Limitation: spacing range is precise, so mis-sizing may require an alternative kit.
SPZOCE GE Interlock Kit for GE Panels
Best for General Electric GE 150/200 amp panels, this kit uses a 1 1/4 inch spacing between the main and branch breakers. It emphasizes safe direction of generator power to selected circuits, aiding continuous operation of essential appliances during outages. It’s a practical choice for GE users who want a straightforward installation with clear compatibility notes. Caution: confirm model and spacing alignment with your GE panel before purchase.
Who it’s best for: GE panel owners needing a dependable interlock to manage generator backfeed. Why selected: explicit spacing and universal installation approach for GE 150/200 amp panels. Limitation: some GE mid-range models may require verification of plug-in neutral configurations.
EXCELFU GE Interlock Kit (125/150/200 Amp)
Best for General Electric GE 150 or 200 Amp Panels, this kit uses a 1 1/4 inch spacing and focuses on preventing simultaneous mains and generator power. It’s suited for users who need a robust backfeed solution with solid reliability for essential circuits. Caution: verify the exact panel model and spacing to ensure compatibility with your GE upgrade path.
XMK Siemens/Murray Interlock Kit for 100–200 Amp Panels
Best for Siemens/Murray 150 or 200 amp panels, this interlock kit supports a 7/8 inch to 1 1/4 inch spacing depending on the model. It’s designed to prevent simultaneous mains and generator power, directing generator power safely to chosen circuits. Choose this if you have a Siemens/Murray panel and want a flexible spacing range. Caution: confirm the exact spacing requirement for your panel model before ordering.
XMK Siemens/Murray Interlock Kit (7/8–1/4 Inch Spacing)
Best for Siemens/Murray 150 or 200 amp panels with 7/8 to 1 1/4 inch spacing, this kit emphasizes a safe, reliable method to direct generator power to circuits. It’s well-suited for users who require a broader spacing option across multiple panel configurations. Caution: ensure your exact model and spacing match before purchasing.
SPZOCE Interlock Kit for Siemens/Murray Panels
Best for Siemens or Murray 150/200 amp panels, this professional interlock kit features a 7/8–1 1/4 inch spacing. It emphasizes safe generator connection while preserving household appliance use during outages. It’s suitable for users who want a broad compatibility range and a straightforward installation process. Caution: verify panel model and spacing to avoid misfit.
Buying Guide: How To Choose The Right Generator Interlock Kit
- Panel compatibility: Confirm your home panel brand (Square D, GE, Eaton, Siemens/Murray) and amperage (150A or 200A) before selecting an interlock kit.
- Spacing between breakers: The critical spec is the distance between the main and branch breakers. Common values include 1/4 inch to 1 3/8 inch; ensure your chosen kit’s spacing matches your panel’s layout.
- Installation considerations: Look for kits that include installation hardware (drill bit, screws) and clear manuals. Some kits require drilling or neutral terminal handling; ensure you’re comfortable with the process or hire a licensed electrician.
- Safety and backfeed control: A good interlock should physically prevent both mains and generator supply at the same time, reducing risk during outages. Look for explicit safety descriptions in the product features.
- Best use cases: If you want to backfeed essential circuits only, choose a kit with straightforward control and clear indications for what’s powered by generator vs. mains.
- Limitations and compatibility notes: Some interlocks pair with specific models or neutral configurations (plug-in neutral vs. non plug-in neutral). Verify these details to avoid installation issues.
Frequently Asked Questions
- What is a generator interlock kit? A generator interlock kit is a device that prevents backfeeding from a generator to the utility grid and ensures generator power is directed safely to selected circuits in your home.
- Do interlock kits require professional installation? Many can be installed by a capable DIYer with basic electrical knowledge, but some panels and configurations are best handled by a licensed electrician for safety and code compliance.
- Can I use an interlock kit with any panel brand? Interlock kits are model-specific. Confirm compatibility with your panel’s brand, model, and amperage before purchase.
- What spacing should I expect between breakers? Spacing commonly ranges from about 7/8 inch to 1 3/8 inches, depending on the panel and interlock model. Match the kit’s spacing to your panel’s requirements.
- Is backfeeding unsafe? When done correctly with an interlock kit, backfeeding is controlled and safe, preventing simultaneous mains and generator power and protecting appliances and lines.
- Do interlock kits affect warranty or code compliance? Using a suitably rated interlock kit per the panel manufacturer’s guidelines helps maintain code compliance; consult your local electrical code and installer for specifics.